Pathogenic potentials and shedding probability of Salmonella enterica serotype Kentucky in experimentally infected backyard chicken

Objective: Salmonella is a widely-reported zoonotic bacterial pathogen and human
infection is mostly attributed through direct or indirect contact with chickens.
Salmonella Kentucky (S. Kentucky) is one of the motile serovars which has recently
been identified from both poultry and human samples in Bangladesh. This study
was conducted to assess its pathogenic potentials and shedding probability in
backyard chicken.
Materials and methods: We infected 22 backyard chickens orally, each with 106
cfu of Salmonella Kentuckey, which were then observed for 23 days to enlist clinical
signs, gross and histo-pathological changes. Polymerase chain reaction (PCR) for
Salmonella was applied on some representative samples to identify the presence of
Salmonella.
Results: Four chickens were sacrificed and the internal organs were examined to
observe gross and microscopic tissue changes. Some reactive changes were seen
in spleen during prolonged course of infection. The probability of S. Kentucky
shedding was 77% (95%; CI 54-90%) on DPI 2, 41% (95%; CI 21-60%) on DPI
12 and 13% (95%; CI 3-31%) on DPI 21. The survival probability of the infected
chickens was 50% (95%; CI 28-68%) on DPI 6, 32% (95%; CI 14-51%) on DPI
15 and 14% (95%; CI 3-31%) on DPI 23.
Conclusion: Zoonotic S. Kentucky strain of human non-typhoidal clinical cases of
gastroenteritis has potentials to produce clinical signs such as reduced feed
uptake, watery or pasty fecal droppings and lesions, such as catarrhal enteritis and
typhlitis.